3.1 The Kababish Arabs-pastoral nomads
3.2 The Berti - Mixed farmers in a dry area
3.3 Seminomadic Tuareg
3.4 Factors influencing the adoption of traditional strategies
This chapter takes a detailed look at some societies which exemplify the main livestock production systems in tropical Africa, and shows how each of these societies employs one or a combination of the traditional strategies discussed in the previous chapter to overcome water shortage. Since the most complex of the strategies is the one we have termed the "positioning and conservation strategy', emphasis has been given to using as examples societies which best illustrate that strategy. However, the provision of examples to illustrate strategies has a danger. Such examples, drawn from studies of whole societies rather than of individuals, tend to foster the illusion of uniformity within a society, as though all the members every year pursue the same strategy. This 'averaging' of behaviour over whole societies often obscures important differences between the way in which different individuals, or the same individual when subject to different constraints, behave10.
10
Dyson-Hudson has drawn attention to this: 'It is the variations in individual behaviour patterns not the modal behaviour for the entire tribal group which gives the greatest insights...'(Dyson-Hudson, 1972, p. 47).
It has been easiest to find well documented examples of the application of strategies to overcome water shortage among systems of nomadic pastoralism in arid areas, then of mixed farming in semi-arid areas. With some difficulty an example has been found for a seminomadic system. These are the three production systems described in Chapter 1 of this report. No very useful information could be found on mixed farming in high-altitude areas, so no example of this is given. Ranching and small-holder dairy systems have tended to rely, in their water technology, on imported equipment and technology and are there fore, by our definition, not exponents of traditional strategies. The reader is reminded that in describing how societies employ different strategies the present tense is used in connection with evidence drawn from the past, unless it is positively known how the situation has changed since the time when the evidence was collected.
Among the Kababish Arab pastoral nomads of Sudan the following system operates (Asad, 1970). Kababish mainly keep camels, sheep and goats, in that order of importance in terms of biomass. The Kababish rely on grain rather than on livestock products for their main direct food, selling livestock to buy grain. Sheep and goats are sometimes herded together and sometimes separately, in which case the sheep require the more intensive herding. In the summer (hot dry season from February to June) camels need watering once in 9-10 days and sheep once in 4-5 days. Goats last a little longer without water than sheep but are normally watered at the same time. In winter (cool dry season from November to January) camels can go without watering for months and the watering frequency of other species is also greatly reduced.
Sheep are the most selective feeders and goats the least. Because it is a less selective feeder a goat needs a smaller area than a sheep to feed itself, i.e. it can use an area more intensively. As a consequence goats need to travel smaller distances from water points in the dry season in order to find enough to eat. Camels are also more intensive (i.e. less selective) feeders than sheep, but because of their lower watering frequency they can also exploit a much larger area. In normal dry seasons sheep and goats graze up to 18 miles from water and camels up to 35 miles; as a consequence in regions where there are only a few isolated water points camels can exploit an area four times larger than can sheep and goats. In bad dry seasons the radius of grazing for each species greatly increases and, as a consequence, the area livestock can exploit from a single water point almost trebles.
At the peak of summer it is usual for all household's livestock to be watered at the same well-field, although (as mentioned earlier) some camels may be sent off to water at distant boreholes so as to reduce the strain of watering by hand. At the well-field one household may 'owe' one or several wells which it may use exclusively or in cooperation with other households. Such wells have to be dug each year, and may need to be re-excavated and relined several times during a summer; they are normally less than 25 feet deep. A well is 'owned' by the household or group who dug it, but any Kababish may dig a well at any well-field and use the pasture around the well-field. Although households tend to return to the same well-field each year there is no rule which compels them to do so and some households do change from one well-field to another. Watering livestock at these impermanent wells is very labour-intensive and requires the labour of many members of the household. The tents of the household will be pitched from as little as 1/2 a mile to as much as 10 miles from the well-field. The better the year and the less dependent the household is for its subsistence on selectively grazing sheep (which need to roam further afield than goats in order to meet their feed requirements), the closer will be the household's tents to the well-field.
Towards the end of the summer dry season, especially if it has been a bad one, those livestock, especially camels and sheep, which are not required for the direct subsistence of the family, may be driven south accompanied by just a few herders, to an area where rain has already fallen. This exodus greatly eases the work of watering animals at the wells and relieves pressure on the grazing around the summer well-fields. When the rains come further north the families and family herds also move away from the well centres in a westerly direction to the rainy-season (July-September) grazing area, where they are subsequently joined by the main herds coming up from the south. The move away from the summer well-fields is not dictated by regulations or even, in most years, by the exhaustion of the summer pasture, but primarily by the desire to end the backbreaking job of watering livestock from wells. During the rainy season the herds drink from surface pools; if from small pools then frequent shifts of camp are required as these pools are exhausted and only small concentrations of the human population are possible. If livestock drink at larger pools then higher concentrations of human population are possible, allowing wider social contacts, but the surrounding pasture is correspondingly over-used, the water becomes foul, and there is more opportunity for thefts, quarrels and the spreading of livestock disease.
After the rains end in September to October the Kababish delay the return to the summer well-fields for as long as possible. The families and their accompanying herds (mainly goats for milk) stay at the big pools in the rainy-season grazing area until those pools dry up between November and January. The reluctance to return to the wells is (again) not imposed by regulations but by the desire to evade the arduous tasks of watering from wells and the long treks to and from well-fields for as long as possible. At this time the main herds, with just a few accompanying herdsman, may move off further northwest to the desert margin for a period. The sheep of the main herds will have to return to the wells earlier, as soon as the exiguous water resources in these areas dry up. The camels will stay out longer, relying on the succulence of vegetation to satisfy their water requirements in this winter time, and their herdsmen will in turn rely only on the camel's milk for their water intake. In good years camels may be able to stay away from the wells up to as late as March.
The Kababish practice most of the strategies already outlined, but to varying extents. From the evidence available they do not appear to put much emphasis on investment in new water supplies (in contrast, for example, to the Somalis of Ethiopia mentioned in the previous chapter), or on adjusting the age and sex composition of their flocks, or on the management and control of water points. Their main emphasis is on the positioning of herds and herders in relation to water supply and in using their summer water points and grazing for as short a time as possible. Given the nature of their water source, and their reliance on human labour to build and maintain the water point and to extract water from it for delivery to livestock, the main factor that influences their activities is the supply of labour. It is the labour constraint that induces them to send some camels off to water at boreholes throughout the summer and to send their main herds off south towards the end of the dry season. Similarly it is the desire to save labour that drives them away from the wells at the end of the summer and delays their return for as long as possible after the end of the rains.
The Berti are Arabic-speaking mixed farmers who live in the west of Sudan in an area where 300-350 mm of rain falls during the 3 months from July to September (Holy, 1974). The Berti practice hoe cultivation, the collection of gum arabic and animal husbandry. Their main source of cash income is gum arabic and of food the crops of millet, sorghum, sesame and melons which they grow themselves. They keep goats, camels and sheep as well as their main livestock, cattle, which they value mainly for their milk. The Berti live in permanent houses in villages around which they plant their crops.
During the rainy season livestock are kept near the villages, watering, where necessary, from temporary sources. They have to move near the villages at this time because all the available labour is required for weeding the crops and it can not be spared to herd livestock in distant pastures. During the long dry season only a few head of cattle are kept in the villages to supply milk for the inhabitants. If the dry-season water points are not more than 2 to 3 hours' walk from the village, the village livestock will be trekked to these water points on watering days. If the water points are further away, water for the village livestock as well as for human use will be transported by camels and donkeys.
The other livestock are kept, during the dry season, in special dry-season camps, in areas that provide better grazing than is available around the villages and which are nearer the dry-season water points. These dry-season water points are of two kinds; sandy river wells and open wells up to 40 m deep. The sandy river wells are used earlier in the dry season and then, when they dry up, to 40 m deep. The sandy river wells are used earlier in the dry season and then, when they dry up, recourse is made to the deeper open wells. Sandy river wells are 'owned' by particular villages and a village may have between one and three such wells. Each well has a 'well-master' (agid al-bir) who is an inhabitant of the village owning it. The well-master organises the communal redigging of the well each year and is responsible for the orderly use of it. People from the village owning the well have a preferential right to use it and people from other villages may only use it if members of the owning village are not doing so11. The well-field (i.e. the sandy river or wadi) in which particular wells are located has a 'well-field-master' (rais al-bir) who is a member of the major lineage in whose territory the well-field is situated. The well-field-master, at the beginning of each dry season, assigns the rights to dig wells in the well-field.
11
It is not clear in the source document (Holy, 1974, p. 109) whether members of other villages are only able to use a well at particular moments in a day when it is not being used by the owning village, or whether their access depends on the owning village not using it at all in that day/week/month.
Open wells (sani) are owned by the maximal lineage in whose territory they are situated. Rights over a well are exercised by a dwell-master' (agid al-bir), who is also responsible for organising the communal work of cleaning and repairing the well. The right to use the well is tied to the payment of a fee at the end of the rainy season following the use of the well. Clearly someone who fails to pay the fee will be debarred from subsequent use of the well, but it is not clear how the right to use it on the first occasion is obtained: the well may be used by tribal aliens and members of other lineages as well as by the lineage owning it. Watering at these open wells is on a 3-day cycle and for each day in the cycle there is a separate 'roster-master' (rais al-dima) who is- responsible for maintaining order at the well on his day in the cycle, a day on which 'water is always drawn by members of the same household'.
Cattle, goats and donkeys are watered every third day in the dry season and camels and sheep every sixth day. Water is drawn by hand, using a leather bag and rope, and then poured into troughs. At the height of the dry season this work requires a team of three or four people of whom all but one (who is supervising the animals as they drink) must be physically very fit. Watering livestock is, therefore, labour-intensive and households which are short of labour, either because they cannot field the minimum team needed to operate the well at all or because their herds are too large for the number of people in the immediate household, have to enter into cooperative agreements with other households in order to provide enough labour. On watering days members of the family who are resident in the village come out to the wells to assist in watering, but there is a conflict between the requirement for labour to water animals at the height of the dry season and the need for the same labour to be clearing new fields for planting.
There is some movement of dry-season livestock camps in relation to water points, in terms both of moving from dependence on one kind of water source, i.e. sandy river wells, to another, i.e. open wells, and of relocating camps into different positions with better access to pasture while still depending on the same water source. But the Berti, because they are tied to permanent villages and the fields around these and to the requirement of providing labour for cultivation, do not have the same flexibility to adjust the positioning of their herds to the availability of pasture and water as do pastoral nomads such as the Kababish. Not only are the Berti more constrained in space but also, because of the competing demand by crop cultivation for labour, they are not able to split up their herds to the same extent as do pastoral nomads. The latter often split up their herds into different species and different types (age, sex, lactation, pregnancy) within species, with each herd receiving the management, in terms of watering, trekking and grazing, best suited to it. Indeed the Berti's livestock receive rather little herding and may, for example, stray off to the watering point on days outside their proper cycle (Holy, 1974, p.88). In any case, cows and goats are expected to go of their own accord to the well on the proper day. Possibly it is because of these limitations on their ability to practice a positioning and conservation' or a 'husbandry' strategy that the Berti seem to have invested more effort into a 'management and control of water points' strategy and into the evolution of a comparatively complex set of water institutions.
Many of the seminomadic groups, occupying areas on the margin between the purely cultivation and purely grazing zones and basing their livelihood on both crop and animal husbandry, have been subject to the greatest changes in their modes of life during the last 30 years as a consequence of demographic pressure, of development programmes which introduced new water supplies, and of political change. The account which follows of seminomads in southern Niger draws principally on Bernus (1981) and Eddy (1979) and refers to the Iullemeden Kel Dinnik Tuareg whose cultivation and dry-season grazing areas-their home base - are located in the Tchin Tabareden Arrondissement. In addition to keeping livestock these seminomads also cultivate millet, sown on sandy soil often on the side of sand dunes, and, to a lesser extent, sorghum cultivated on heavier soils often in valley bottoms. Tuareg society was traditionally divided into a number of social classes, the complexity and functions of which can not be discussed here but are described in Bernus (1981). The social system gave Tuareg 'warlords' the power to control access to the range-lands (Eddy, 1979, p. 384).
The home base of these seminomadic pastoralists is in an area relatively well watered with pans, open wells and, more recently, boreholes (Bernus, 1981, pp. 342-353). In the past in general the migrations of these seminomads followed the same general north-south oscillation as that of the pure nomads also occupying parts of southern Niger, but there were important differences due to the different circumstances and constraints under which they operated.
The most important determinant of the direction of migration for both pure nomads and seminomads was the need to have access during the rainy season to the minerals ('cure salée') in the water of ephemeral pans and in the soil and vegetation 250 km away to the northeast outside the seminomads' home base, as well as the need to conserve the grazing in their home bases for use during the dry season when water supplies further north dry up. The seminomads' main migration was actually longer than that of the pure nomads because the seminomads needed to retreat further south to less dry areas where crops could be grown.
The timing of migration was also different. Pure nomads moved when the relative abundance of water and grazing in different areas dictated this; seminomads were constrained by the crop timetable. Except in the case of the larger or richer families the labour of their herdsmen was required for planting and for weeding at least once after the beginning of the rains before they departed north, and again for harvesting soon after the beginning of the dry season when it hastened their return south once more. In between these times their livestock needed to move out of the home base not only in search of minerals and to conserve dry-season grazing, but also to avoid trampling on the growing crops. Often only young people, especially young men, went on the annual migration, leaving other members of the families to keep an eye on the fields (Eddy 1979, p. 32). In contrast pure nomads moved with their whole families earlier on the onset of the rains and returned later in the dry season.
The herds of seminomads were both smaller than those of pure nomads and less diversified in species -both features reflecting their relatively greater scarcity of labour for herding consequent on the need for it in crop cultivation. In this system in the past neither pasture nor drinking water were particularly critical scarce resources. For these seminomads the main constraint seems to have been shortage of labour for herding and cultivation and the rather complex forces in the Tuareg social structure which limited the rights of subordinate classes to accumulate livestock.
In recent years the pattern has changed as a result of three main factors. Demographic pressure has pushed both cultivating Hausa and nomadic pastoral Fulani northwards into these Tuaregs' home base. The relatively high rainfall years of the 1950s and early 1960s made the expansion of cultivation - especially by the Hausa - possible, although this expansion was checked by the drought of 1968-73 and further encouraged thereafter by the need of previous pastoralists who had lost their livestock during the drought to find an alternative livelihood. The opening of government-operated water points has allowed an enormous influx of livestock, largely but not only belonging to the Fulani, into an area where, in more distant pre-colonial times, Tuareg ascendancy and subsequently private ownership of private wells restricted livestock numbers (Eddy, 1979, p. 133). The number of livestock owned by the Tuareg themselves fell severely during the 1968-73 drought. Whether as a result of greater population pressure and a consequent removal of protective vegetation or of the 1968-73 drought, the surface water sources of the area seem to have deteriorated. Pans dry up earlier in the year and shallow wells no longer last throughout the dry season.
As a result of these factors the previous pattern of land use by these Tuareg seminomads has changed in recent years. For the most part they no longer migrate out of their home base in the rainy season in search of mineralised water and pasture; instead salt is imported and fed to livestock. To migrate out would not, now, as it did hitherto, conserve the grazing for later use in the dry season, since immigrant Fulani herds would eat it in the rainy season instead. Moreover the Tuareg seminomads need as many of their household members as possible to be present in the crop areas during the rainy season to prevent crop damage by other people's herds (Eddy, 1979, pp. 133-134 and 181). There has been some tendency for Tuareg seminomads to give more emphasis recently to crop production than hitherto, partly because loss of livestock during drought has made them more dependent on cropping, and partly because only by planting an area of land to crops can some rights over it be maintained (Eddy, 1979, p. 137); otherwise it is likely to be occupied by an immigrant. Paradoxically the introduction into the area of additional water points, in the form of government-operated boreholes and concrete-lined open wells, has probably worsened the access to water and grazing of the original Tuareg people who used the land. Some of their previous water sources have dried up while grazing needs to be sought further afield at the end of the dry season as a consequence of its early exhaustion by the immigrant herds. Both these processes have been facilitated by the new water supplies at which control of access is not exercised.
In this example both traditional positioning/conservation and management/control strategies were exercised in the past; investment, composition and husbandry strategies were, in comparison, less important. Political events, i.e. on the one hand the suppression by the French colonial power of the Tuareg social system and the pattern of control of access to grazing and water which derived from it, and, on the other hand, the opening of new government-operated water supplies, were the main causes of the collapse of the old system. Nothing has yet grown up to take its place in providing a system for coping with shortages of grazing and water. A main reason for this is probably that the area is now occupied by three main ethnic groups, Tuareg, Hausa and Fulani, of whom the Hausa are in the dominant political position (Eddy, 1979, p. 137) and probably have the least interest in increasing the efficiency of livestock production. Given the inter-ethnic competition for resources and the inter-ethnic strife that the imposition of a new system for controlling access to water and grazing would likely arouse, it is, perhaps, not surprising that the politically dominant group have not thought it worth investing effort in evolving a new system.
The detailed examples given above show some of the ways in which different factors influence the extent to which particular strategies are undertaken; further evidence comes from other studies whose details are not reported here. The ensuing paragraphs discuss the influence of the main factors.
Foremost among these is the supply of labour for herding and watering in relation to competing demands for its use. As already pointed out the optimum spacing of livestock in relation to sparse water supplies requires that there be sufficient herding labour available for it to be possible to split up a person's or a household's total livestock holding into separate specialised herds (in terms of species, age, etc.), each with its own system of grazing, watering and management. Where the separate herds have to be reunited daily, e.g. to be enclosed at night in stockades for protection from predators, or so that milking animals can suckle stock, this requires a careful spacing of the encampment. On the one hand, the encampment must not be so far from water that young stock cannot be trekked there or water be brought to them by beasts of burden (Smith, 1978, p. 85) or that members of the household cannot walk to and from the water point to assist in the task of watering. On the other hand, the encampment must be sufficiently far from the water point that mature stock grazing out from the camp can get access to the relatively ungrazed outlying pastures. The camp site will need to be changed from time to time in response to the changing availability of pasture.
Some of the elements in a husbandry strategy, e.g. night grazing or extended grazing hours, also require abnormally high amounts of labour. Some elements in an investment strategy, e.g. constructing and maintaining dams, hafirs and wells of different kinds, are also labour-intensive. The greater the supply of labour available for these purposes the greater the extent to which livestock-owning households or societies will be able to implement these strategies effectively. When the supply of labour is inadequate to carry out the strategies properly for the existing number of animals, either the performance of livestock will suffer as they fail to overcome the problems inflicted by water shortage, or else the number of animals will have to be reduced to match the labour available.
Competing demands for labour may divert this labour supply. In some societies a substantial part of the labour force which would otherwise have herded livestock has, in recent years, attended school (Gulbransen, 1980, p. 173), or migrated outside the area where livestock are kept to earn income as wage-labourers elsewhere (Dahl, 1979, p. 85; Bonte, 1975, pp. 254-259; Fortmann and Roe, 1981, p. 143). In other cases labour is needed for crop cultivation inside the area. The consequences in all these cases tend to be the same - the livestock get less attention. For example the livestock of sedentary Fulani farmers in Nigeria have a 'grazing day' (i.e. time spent outside the cattle enclosure or camp) 20% shorter on average over the year as a whole, than those of their (semi) nomadic wholly pastoral counterparts. In the critical dry season (January to May) 'sedentary' cattle start their grazing day almost 2 hours later than 'nomadic' ones and their grazing day is up to 33% (in April) shorter (Van Raay, 1975)12. When labour is tied to permanent habitations or fields of crops it can probably not be optimally positioned in a camp between water supply and pastures. Many settled livestock owners in West Africa get round this competition between the demands for labour from cultivation and herding by entrusting their livestock to nomadic herders.
12
Van Raay does not give data for allocation of human labour. Data from a region in Upper Volta (Delgado, 1979) at the same latitude as Van Raay's sedentary farmers show that from the end of March onwards farmers are engaged in land preparation for the coming season's crop, an activity which reaches a peak in May (Delgado, 1979, p. 111). Van Raay himself came to the conclusion that the livestock management system of settled cattle is more efficient (by the criterion of the ratio between protein intake and requirement) than the nomadic system in the dry part of the year; but he reached this conclusion on the basis of arbitrarily allocating to the Fadama (lowland) herbage, which makes up 50-80% of settled livestock diets (and from which nomadic livestock are excluded) in the dry part of the year, a protein content double that which has been actually measured.
Watering livestock is another important competitor with herding for a scarce labour supply. In this case the type of water source at the water point can be of crucial importance. In Mali one herder can herd up to 50 camels during the dry season if they drink from a dam or river where livestock have direct or near-direct access to the water source; but if water has to be laboriously raised by rope and bag from 20 m deep open wells, an extra adult (probably a man) is required for half a day every 5 days to help in watering (Swift, 1979, Ch. 5). In the case of cattle two men can cope with 100 head, except for watering at these open wells when an extra two adults will be required for several hours every other day. In watering from open wells there are both economies of scale and diseconomies, e.g. where different herds and species get intermixed, and confusion, and sometimes injury to animals, results (Marty, 1972, p. 33 and Annexe p. 42; Swift, 1979, p.203). In cases where a certain minimum size of watering team is required to draw any water at all (Holy, 1974, p. 88; Helland, 1980, p. 66) there can be very substantial decreases in labour requirements (per head of livestock) for watering as herds are increased up to the optimum size, because once the team has taken the necessary time to assemble at the well it requires proportionately little extra time to water an extra animal.
We can illustrate this with a composite example that uses realistic technical coefficients from various sources (Holy, 1974; Swift, 1979; Torry, 1977; Bernus, 1981). A minimum team of four persons is required and they have to walk 2 hours from camp to well and 2 hours back again; the well yields 500 litres per hour from a depth of 20 m and cattle drink just over 30 litres at a single watering, i.e. 16 cattle can drink per hour; watering is hard work and a team cannot do it for more than 5 hours maximum per day. For a herd of only 10 cattle the labour input (walking to the well and then watering) would be 1.85 man-hours per head of cattle on a watering day; for a herd of 80 cattle it would be 0.45 man-hours per head; but for a herd of 90 cattle an additional watering team would be required and overall (i.e. over all the 90 head) the labour input would rise again to reach 0.61 man-hours per head on a watering day.
The large requirement for human labour to water livestock from open wells, and from many sandy river wells, has had important effects, primarily in terms of limiting the total number of livestock kept, but also in respect of determining the opportunities for advancement of those whose herd sizes are greater (i.e. the rich) or less (i.e. the poor) than the size of herd which is optimal for watering at open wells. Substituting either boreholes, where water is extracted and delivered to the livestock by mechanical pump, or permanent reliable dams and hafirs, where livestock have direct or near-direct13 access to the water source, in place of labour-intensive wells sometimes greatly increases the number of livestock which can be kept in an area (e.g. the case of Niger - see Marty, 1972, p. 82). Labour released from watering duties can then be employed (although it may not be) in carrying out better herding and husbandry. It also makes it possible for the rich to accumulate bigger herds than would otherwise have been the case, by removing the need to take on extra labour to water their herds at wells and the steady drain on resources to pay this labour that is the usual result14. Boreholes, either because they are usually government owned and therefore outside the traditional community controls, or because their technology puts power to control them in the hands of technicians who can then be threatened or bribed, may also give advantages to the rich and powerful who can get priority for their own herds at the expense of others (Marty, 1972, p. 34). Probably, however, such privileges due to power and position always exist at water points.
13
'Near-direct' access covers instances where herders ladle water from the water source more or less horizontally into water troughs, without great expenditure of human energy, in order to prevent livestock fouling the water source.14 In some societies, however, slaves or near-slaves watered (and continue to water) the livestock of the powerful for little reward.
Boreholes and dams, however, may also benefit the poor by making it possible for them to carry on other income-earning activities in addition to livestock raising without the total absorption in watering that labour-intensive wells require. In Niger (Marty, 1972, pp. 82 and 92) the poor who are thus able to pursue other occupations are among the strongest proponents of boreholes. In Botswana female-headed households are significantly less frequent users of sandy river wells than male-headed households, possibly because of the high annual labour requirements for redigging such wells (Fortmann and Roe, 1981, p. 73). Providing new labour-sparing water sources to poor or weak households may help them to continue to be stock raisers.
To an extent obstacles to carrying out the various strategies that are caused by labour shortage can be overcome by social institutions that facilitate cooperation between households and other groups, so that labour and livestock can be pooled in such a way as to achieve optimum combinations. Herding groups constitute one such institution, as do well-councils and well-masters (Helland, 1980; Holy, 1974), and lead to the formation of teams to maintain and operate wells. Other institutions permit the adoption of children from labour-surplus by labour-deficit households or the entrustment of livestock by farmers or large herd owners to pastoralists with the capacity to take on more animals. Some societies possess such institutions while others do not. It is difficult to tell how much 'social structure' is an independent factor in this, encouraging or inhibiting cooperation, or how much it merely reflects the degree of need for cooperation. Certainly in some cases it seems to be an independent factor. In the central highlands of Ethiopia, for example, so intense is suspicion of neighbours that the size of flocks which are herded independently are quite remarkably small; 20% of all sheep and goat flocks (i.e. herding units) consist of five or less animals and 35% consist of 10 or less. This occurs because, in spite of general complaints about shortages of shepherds, no one is prepared to entrust their livestock to someone else (Cossins and Yemerou, 1974, p. 14; Watson, 1973b, Table 7).
Reliability, both of water supply and of the surrounding pasture, may be an important element in determining to what extent one strategy is followed rather than another. The societies which have developed the most complex institutions for managing and controlling water supplies, e.g. the Berti (Holy, 1974) of Sudan and the Borana of Ethiopia, are either sedentary15 or at least fairly regular in their use of water and pasture. Water is in scarce supply (or at any rate it is difficult to extract from deep open wells) but both water and pasture vary comparatively little from year to year in contrast to neighbouring areas. Thus settlement and moderate regularity provide the opportunity to develop complex social institutions. Helland (1980) emphasizes the time and effort that an individual needs to invest in social and political relations if he is to maintain and strengthen his watering rights at the important Borana wells. That kind of continuous maintenance of social relations inside a group with a more or less fixed membership is exceedingly difficult in a highly fluctuating and unpredictable environment, where groups are liable to have to form and disperse at short notice in response to the need to adapt human and livestock densities to local and temporary variations in grazing. Moreover, even if the required investment in social relations can be maintained in order to establish efficiently functioning institutions at particular water points, there will be no guarantee that the investor will reap the fruits of his investment; a bad season may force him to go and seek grazing elsewhere where the rainfall in that year has been better.
15
The Borana have the system of 'dry' or 'fallow' herds already referred to, in which the dry herds and their few herdsmen are much less sedentary than the 'milking' herds and other humans. Although the dry herds are fairly opportunistic in their movement, this does not invalidate the present argument since the herders of the dry herds are not usually the heads of households who need to develop and cooperate in social institutions.
Next door to the Borana of Ethiopia but in a much more unreliable environment are the Somalis of the Horn of Africa. Because of this unreliability they have a highly opportunistic land-use system in which large sections of the population may switch even their fallback dry-season watering points from year to year. In contrast to the Borana they have much less complex institutions for the management and control of water points. However, their manipulation of livestock and people in space and time is much more complex. This is well illustrated by Cossins (1971a).
Other kinds of uncertainty (as well as that due to the natural environment) can also effect the extent to which livestock owners are willing to invest time and energy in institutions to carry out a strategy of managing and controlling water points. Where different ethnic groups use the same territory and watering facilities, and where one of these ethnic groups is not clearly superior in power and status to the others, it is extremely difficult to decide upon, by consensus of all the users, and then to enforce, the regulations for management and control. In northern Kenya, Borana efforts to manage the efficient use of water at dams broke down when the government ceased to enforce the previously strict restriction of pastoralists within tribal areas -Somali pastoralists came to water at the same dams (Dahl and Sandford, 1978, p. 41). Thereafter not even the Borana observed the regulations because they were sure the Somalis were not doing so. In general when governments construct or take control of water points, the uncertainty caused by fluctuations in government policies prevents the growth of the kind of management system found at non-government water points in the same areas. Both ethnic mixing and government ownership have combined in Niger to produce a situation in which the management of the water at boreholes is extremely poor (Marty, 1972, pp. 33 and 43).
Another important factor influencing the choice of strategy is the extent to which crop cultivation spreads into areas previously used exclusively by nomadic pastoralists. When water supplies are sparse and investment in multiplying them is expensive, and where nomadic pastoralism is the only system of land use, livestock owners will probably prefer a strategy - of the kind illustrated by the example of the Kababish Arabs - of carefully positioning different species and classes of livestock in space and time so that each has an optimum balance between access to feed and access to water. But this strategy often becomes infeasible where the spread of cultivation, often by an immigrant ethnic group, around the fallback water points prevents grazing of this area by the livestock with the highest water requirements, or involves pastoralists in constant disputes over damage done to crops while bringing their livestock to water. The spread of cultivation may involve the abandonment of one strategy in favour of another.
The factors already mentioned, labour supply and alternative demands for it, the unreliability of the natural and social environment, and the extent to which crop cultivation extends into areas previously reserved exclusively for nomadic pastoralists, largely explain why some strategies are pursued more in some production systems than in others.
